For within-group comparisons of marker levels between initial (6 h) and follow-up time points, a significant increase was detected in patients with infection for LBP (6 h versus 12 h: P = 0.001, 6 h versus 24 h: P = 0.001, 6 h versus 3 d: P = 0.01) and CRP (6 h versus 12 h: P = 0.002, 6 h versus 24 h: P = 0.001, 6 h versus 3 d: P = 0.002). This evidence concerns the gene CRP and infection.